Kiyo Terauchi (寺てら内うち きよ Terauchi Kiyo) is a servant of the Butterfly Mansion.
Kiyo is a girl with light skin and a set of circular, black eyes. She has shoulder-length black hair with thin bangs framing her face, along with two pink butterfly clips on each side of her head.
Kiyo wears a long, white nurse dress tied with a dark, reddish-pink bow around her waist. She also sports white socks and shoes.
After her family had been killed by Demons, Kiyo was taken in by the Butterfly Mansion.
Muzan Kibutsuji (鬼き舞ぶ辻つじ 無む惨ざん Kibutsuji Muzan?) is the main antagonist of Demon Slayer: Kimetsu no Yaiba. He is the Demon King, the first of his kind, as well as the progenitor of all other Demons in existence.
A millennium ago, Muzan was turned into a Demon while trying to cure his own terminal illness, and his goal since then was to live without the fear of death and gain true immortality. He attempts to accomplish this by getting rid of his weakness of the sunlight which he is currently doing in 2 ways: finding the Blue Spider Lily or creating more Demons in hopes that one day one would be able to conquer their weakness of the sunlight.
Muzan is also the one responsible for slaughtering the majority of the Kamado family and transforming Nezuko Kamado into a Demon.
